Tenter chains and clips



Feb. 15, 1966 J. c. NASH 3,234,622

TENTER CHAINS AND CLIPS Original Filed Dec. 11, 196] 2 Sheets-Sheet 1 W'1? 'W II Y 0 .mo 375 j is oi'o 010 JOHN C RA NOON NA 5H F1 5 BY ATTORNEV Feb. 15, 1966 J. c. NASH TENTER CHAINS AND CLIPS Original FiledDec. 11, 1961 2 Sheets-Sheet 2 INVENTOR.

JOHN CRANDON NASH A TTORNEV United States Patent 3,234,622 TENTER CHAINSAND CLIPS John Crandon Nash, Providence, R.I., assiguor, by mesneassignments, to Bevis Industries, Inc., Providence, R.I., a corporationof Florida Original application Dec. 11, 1961, Ser. No. 158,269, nowPatent No. 3,180,001, dated Apr. 27, 1965. Divided and this applicationOct. 26, 1964, Ser. No. 406,302 2 Claims. (Cl. 26-61) This inventionrelates to tentering machines and more particularly to the tenter clipswhich make up a tenter chain of a tentering machine.

One of the objects of the present invention is to improve the tenterclip structure whereby the tenter chain cannot be distorted out ofalignment.

Another object of the present invention is to improve a tenter clipstructure whereby the pivot pins serve the single function of permittingthe links of the chain to pivot thereon.

Still another object of the present invention is to provide a unitarytenter clip structure with a base plate having cam means on oppositeends thereof which limits the relative pivoting motion between tenterclips.

This application is a division of patent application Serial No. 158,269,filed December 11, 1961, for a Tenter Clip.

Other objects of the present invention will be pointed out in part andbecome apparent in part in the following specification and claims.

Referring to the drawings in which similar characters of referenceindicate corresponding parts in all the figures:

FIGURE 1 is a schematic view of a tentering machine.

FIGURE 2 is an enlarged fragmentary plan view of a tentering machinechain and sprocket.

FIGURE 3 is a perspective view of the new and improved tenter clip.

FIGURE 4 is a perspective view of the new and improved tenter clip inupside down position.

FIGURE 5 is a bottom plan view of a series of the new and improvedtenter clips.

FIGURE 6 is a front elevational view of a series of the new and improvedtenter clips.

FIGURE 7 is a fragmentary cross sectional view taken along line 7--7 ofFIGURE 6.

FIGURE 8 is a bottom plan view of a plurality of the new and improvedtenter clips illustrating freedom of movement in one direction.

FIGURE 9 is a bottom plan view of a modified form of base plate used onthe new and improved tenter clip.

FIGURE 10 is a front elevational view of FIGURE 9.

FIGURE 11 is a fragmentary cross sectional view taken along line 11-11of FIGURE 10.

FIGURE 12 is a view similar to FIGURE 9, illustrating the limitedpivotal movement, between adjacent tenter clips, in one direction.

FIGURE 13 is a view similar to FIGURE 9, illustrating the limitedmovement between adjacent clips whereby justapositioning betweenadjacent clips is eliminated.

FIGURE 14 is a fragmentary enlarged view of the cam surfaces on themodified form of clip shown in FIG- URES 9, 12 and 13.

FIGURE 15 illustrates a modified form of tenter clip body which may beused instead of the cam surfaces shown in FIGURES 3, 4 and 5.

In this specification the term cloth includes any type of web materialsuch as cotton, wool, synthetic fibers, plastic film, aluminum foil,etc.

Referring to the drawings, and particularly to FIGURE 15, the tenterclip comprises a horizontally disposed base 3,234,622 Patented Feb. 15,1966 ice 10, a vertically upstanding body 12 and a pair of arms 14, 16which project sidewise from body 12 to overlie base 10. Pivotallymounted between arms 14, 16 on a pintle 17 is a jaw 20. Between thelower edge 20A of jaw 20 and base 10, the cloth (not shown) is grippedas the tenter chain moves along a rail (not shown). When the tenterchain reaches a sprocket such as 26 or 27 at the delivery end of therail a suitable cam (not shown) engages an upstanding arm 28 of thepivoted jaw 20 causing lower edge 20A to swing away from base 10 anddisengage the cloth.

Base 10 is provided with a depending central yoke or arm 60. A bottomplate 61 is integrally attached to the lower end of arm 60. A face 62 isprovided in arm 60 for purposes which will presently appear.

With reference to FIGURES 3, 4, 5 and 6, a modified form of tenter clipis illustrated, comprising a horizontally disposed base 10A, avertically upstanding body 12A and a pair of arms 14A, 16A which projectsidewise from body 12A to overlie base 10A. Secured to base 10A is abearing plate 18 and pivotally mounted between arms 14A, 16A on a pintle17A is a jaw 19 having an inserted strip 22 at its lower edge betweenwhich and the plate 18 the edge of the cloth (not shown) is gripped andreleased in the same manner as described with reference to FIGURE 15.Upstanding arm 28 and 28A serve like functions.

In an embodiment of the present invention shown in FIGURE 6 and 7, thebodies of two adjacent clips are connected together by roller links,generally indicated by reference numeral 29. Each roller link has a pairof plates, an upper plate 30 and a lower plate 32 separated by a roller36 which functions as a spacing sleeve and a roller bearing incooperation with the teeth of the sprocket. Base 10A may be providedwith a slot 11. An axle pin 37 provided with an enlarged head 39 passesthrough an orifice 41A in base 10A with head 39 located in slot 11. Axlepin 37 also passes through orifices in upper plate 30, roller 36, lowerplate 32, and as will presently appear, orifice 43A, where axle pin 37may be secured by a drive fit.

In the modified form of axle construction illustrated in FIGURE 11, axlepin 37A is provided with a riveted end 373 located in a counterbore 42of orifice 43 located in bottom plate 61. Slot 11 is dispensed with.Head 39A of axle pin 37A engages the top surface of base 10'. Roller 36Ais smaller in diameter than roller 36 to accommodate a different toothtype of sprocket wheel and to provide for a different type of guidemeans.

When the roller link shown in FIGURE 7 is employed, roller 36 engagesthe guide rail (not shown). When the roller link shown in FIGURE 11 isemployed face 62 of arm 60 engages the guide rail (not shown).

In applying such roller links 29 to the present tenter chain, the bottomplate 61 serves as the supporting memher for lower plate 32, therebyfreeing axle pin 37 from the heretofore function of uniting the upperplate 30 with the lower plate 32. The axle pin 37 in addition to servingas a connecting pin between plates 30', 32 also serves to hold theroller links against the twisting action imparted by the sprockets andagainst the centrifugal force generated by the sprockets on the rollerlinks 29. In the present embodiment bottom plate 61, in addition tosupporting bottom plate 32, is so shaped as to afford either cam meansor cam means having a plurality of gear teeth arranged so as to keep thetenter chain as a whole in proper alignment as it moves away from thesprockets.

Reference is now made to FIGURES 9, 12, 13, 14 and 15 where cams areformed in opposite edges of bottom plate 61. The center distance 49between orifices 43 in the same bottom plate 61 is determined by thepitch of the teeth of the sprocket 26. The center distance 51 betweenorifices 43 in adjacent bottom plates 61 is determined hy the size ofthe roller 36A and the pitch of the teeth of the sprockets. Distances49, 51 are standard in the tentering chain art.

A circle 5 isscribed from .the center of orifice 43. The width '53 ofbottom plate 61 is equal to the diameter of circle 5. Two parallel sides55, 57 are thereby provided in bottom plate 61. An edge 59 tangent tocircle 5 and located at an angle of ninety degrees to the two parallelsides 55, 57 is also provided in bottom plate 61. A surface 70 isprovided at an angle of approximately twenty five degrees from surface59 andtangent to circle 5. Surface 70 may be termed an angular surface.The points of tangency ofsurface 70 with circle -5 will-always be belowa horizontal center line passing thru the axle pins or the center oforifices 43. The points of tangency of surface 70 with circle 5 willalways be below a horizontal center line passing thru the axle pins orthe center of orifices 43. Thus a cam is formedin opposite edges ofbottomplate 61 consisting of two portions. One'portion consistsof asurface .59 perpendicularto the parallel sides 55, 57. Theother surface.70 is at an angle to surface 59. .Circle 5 is small enough to provide aslight clearance 69 between adjacent bottom plates 61. As will be seeninFIGURE 13, clearance 69 allows adjacent surfaces 59 to pivotally move.in a relative sliding action. However, the clearance is small enough toprevent adjacent bottom .plates 61 from pivoting intoa juxtaposi tion.Thus adjacent tenter clips cannot become misaligned. FIGURE 12illustrates the limited pivotal movement allowed by surfaces 70-011adjacent bottom plates 61. This movement allows the tenter clips topivot around sprocket.26.

Corners 3 formed in the opposite edges of bottom plate 61 at theintersection of surfaces 59 with surface 55, abut withthe correspondingcorners on adjacent clips to strictly limit the pivotal movement betweenadjacent clips in a. direction oppositeto the direction shown in FIGURE12.

In the modified form of bottom plate 61A illustrated in FIGURES 3, 4, 5.and 8, gear teeth 80 are provided in surfaces which are equivalent tosurfaces 59, 70 of FIG- URES 9, v12, 13, 14 and 15. Teeth 80 serve thefunction of horizontally aligning adjacent bottom plates 61A, therebypreventing one bottom plate 61A from slipping into a juxtaposition inrelation to an adjacent bottom plate 61A when clearance distance 69 isgreat enough to permit juxtapositioning to take place.

Referring toFIGURE 1 wherein is illustrated a schematic view .of atentering machine, reference character A indicates the head or clothentering end of the machine. Reference character B indicates the clothdischarge end of the machine.

The tenter chain, generally indicated by reference character 1, is aflexible unit. Sprockets 2, 3, are idler sprockets. Sprockets26, 27 arethe driving or pulling sprockets. The tenter chains are taut in thelength between sprockets Zand 26, and 3 and 27, due to the pull exertedby sprockets26, 27 in the direction of arrows 7, 8. The pull sides ofthe tentering chains are indicated at C and D. The slack sides of thetentering chains are indicated at E and F. The greatest slack .in thetentering chains is at points Y and Z. It is at these points, Y, Z, thatbuckling of the tentering chains is apt to occur. The buckling may takethe form of juxtapositioning of adjacent clips. The present invention isdirected to prevent this buckling andjuxtapositioning.

At points Y, Z, the tenter chains are disengaged from the :respectivesprockets and the chains have not as yet reengaged the respective guiderails.

Centrifugal force at points Y, Z also tends to throw adjacent clips intoa juxtaposition. In addition, the roller links 29 frequently do not peeloff the sprocket teeth. The sticking of the rollers 36 or 36A to theteeth of the sprocket wheel also causes a juxtapositioning of adjacenttenter clips. This sticking occurs through the accumulation of dirt orthrough the lack of proper lubrication.

The tenter clips are under-stress and strain at sides C, D because thecloth (not shown) tends to pull the tenter clips C, D toward each other.As the tenter clips approach sprocket wheels 26, 27, respectively, theclips release their grip on the cloth. The clips, forming the tenterchain tend to buckle at the loss of the tension of the cloth. However,since the cloth release is approximately at the points E, F or point oftangency of the tenter clips with the sprocket teeth, G, H,respectively, the buckling action is delayed until the tenter clipsleave the point of engagement with the teeth G, H. As soon as the tenterclips leave the respective points of tangency and before the tenterclips engage the guide rails (not shown) of the tentring machine, thetenter clips tend to buckle into a juxtaposition in relation to adjacenttenter clips. Such points ,or areas of buckling occur at points Y, Z, inthe respective tenter chains. Such buckling or jamming results in costlybreakdowns of the tentering machine. The strain on the tenter clips orrather on the pintle or axle holding the roller links is very great. Innormal usage, the axles frequently twist out of alignment or break. Inorder to overcome this undesirable condition applicant has removed thefunction of the axle of holding a bottom plate to a base as illustratedand described in United States Patents No. 2,285,820 and No. 2,496,475and replaced this function with the central yoke or arm 60. Thusapplicant provides bottom plate 61 as a unitary structure with base 10.Such a structure can withstand the stress, and twisting strain at pointsY, Z. In addition the axle structure for the roller links is simplifiedand long lasting. Applicants bottom plates 61, 61A are provided withcontours which preclude movement between tenter clips in a directionaway from the guide rail so that a juxtaposition between clips isphysically impossible.

Applicants tenter chain can be operated athigher linear running-speedswith an absolute degree of safety against misalignment between tenterclips. Thus, inherently the problem of preventing juxtaposition betweententer clips has existed since the first tentering machine came intouse.

To clarify the language in the claims, orifice 41A will be termed afirst upper axle orifice. Orifice 413 will be termed a second upper axleorifice. Orifices 43A and 43B will be termed, a first lower axle orificeand, a second lower axle orifice, respectively. Axle pin 37 will betermed a first axle pin. Axle pin 37B will be termed, a second axle pin.

Having shown and described preferred embodiments of the presentinvention by way of example, it should be realized that structuralchanges could be made and other examples given without departing fromeither the spirit or scopeof this invention.

What I claim is:

' 1. A tenter chain comprising, in combination, a series of tenter clipseach havinga body, a bottom plate and a rail engaging central yokefastening said bottom plate in spaced relation to said body, said bottomplate underlying said body, axle pins extending through said body andfastened in said bottom plate, and providing separated bearingportionsintermediate said body and bottom plate, a roller link mounted on abearing portion of one tenter clip and on a bearing portion of anadjacent clip thereby to connect the tenter clips together, said bottomplate having male gear teeth at one end and female recesses at the otherend, the male teeth of one bottom plate engaging corresponding femalerecesses of an adjacent bottom plate to thereby maintain the tenterchain in alignment.

2. A tenter chain comprising in combination a series of tenter clipseach having a horizontally disposed base, a vertically upstanding body,and a pair of arms which project sidewise from said body to overlie saidbase, a jaw having a lower edge, a pintle pivotally mounting said jaw tosaid pair of arms, said lower edge engaging said base in grippingposition, an arm integral with and depend ing from said base, said armconstituting 'a rail engaging central yoke, a bottom plate integrallyfastened to said arm, two axle pins, one on each side of said arm,secured in both said base and in said bottom plate, roller linkspivotally mounted upon said two axle pins thereby to pivotally connectadjacent tenter clips together, opposite sides of said bottom platehaving gear teeth formed therein, the gear teeth on adjacent clipsmeshing to maintain adjacent clips in arcuate alignment during thetravel of the tenter chain around a sprocket and in horizontal alignmentbefore engagement with a guide rail.

6 References Cited by the Examiner UNITED STATES PATENTS 2,096,28310/1937 'Lane 26-61 5 2,178,892 11/1939 MacKnight 26-61 2,285,820 6/1942MacKnight 2661 2,496,475 2/ 1950 Jerauld et a1 26-62 3,058,191 10/1952Nash 26-62 10 ROBERT R. MACKEY, Acting Primary Examiner.

DONALD W. PARKER, Examiner.

1. A TENTER CHAIN COMPRISING, IN COMBINATION, A SERIES OF TENTER CLIPSEACH HAVING A BODY, A BOTTOM PLATE AND A RAIL ENGAGING CENTRAL YOKEFASTENING SAID BOTTOM PLATE IN SPACED RELATION TO SAID BODY, SAID BOTTOMPLATE UNDERLYING SAID BODY, AXLE PINS EXTENDING THROUGH SAID BODY ANDFASTENED IN SAID BOTTOM PLATE, AND PROVIDING SEPARATED BEARING PORTIONSINTERMEDIATE SAID BODY AND BOTTOM PLATE, A ROLLER LINK MOUNTED ON ABEARING PORTION OF ONE TENDER CLIP AND ON A BEARING PORTION OF ANADJACENT CLIP THEREBY TO CONNECT THE TENTER CLIPS TOGETHER, SAID BOTTOMPLATE HAVING MALE GEAR TEETH AT ONE END AND FEMALE RECESSES AT THE OTHEREND, THE MALE TEETH OF ONE BOTTOM PLATE ENGAGING CORRESPONDING FEMALERECESSES OF AN ADJACENT BOTTOM PLATE TO THEREBY MAINTAIN THE TENTERCHAIN IN ALIGNMENT.